Commissioning responsibility matrix: who executes, witnesses and accepts each level

A data center commissioning programme is usually described in five levels, from the factory test of a single switchboard to the integrated systems test of the whole facility. The levels say what is tested. They do not say who carries out each test, who attends it, who checks the procedure and the result, or who decides that the level is complete. That allocation is the responsibility matrix. Most disputes at the end of a project, about a failed scenario, a missing record or a retest nobody priced, trace back to a matrix that was never written or was written too late.

Why the matrix belongs in the tender documents

ASHRAE Guideline 0 and ASHRAE Standard 202 treat commissioning as a process that starts with the Owner’s Project Requirements and runs through design, construction and occupancy. For the matrix, the practical consequence is that it has to be in the employer’s requirements before the main contract and the equipment packages are tendered. A vendor that has not priced an engineer at the factory test, a contractor that has not priced load banks, fuel and a controls specialist for the integrated test, and an operator whose staff have not been released to witness the functional tests will each treat those duties as variations. Written into the tender documents, the same duties are priced once, by every bidder, on the same basis.

The five levels are an industry convention rather than the defined terms of a single standard, and contracts number and name them differently. The matrix should therefore describe each level in words: what it verifies, what must be complete before it starts and what record it leaves.

Parties, titles and the four marks

Six parties appear in a typical matrix. The vendor supplies the equipment and starts it up. The installing contractor installs it, holds the site safety responsibilities and operates the plant during testing. The commissioning manager, appointed by the owner, sets what must be demonstrated, reviews the procedures, witnesses the tests and accepts each level. The owner’s engineer, either the designer of record or the owner’s technical adviser, reviews procedures and results against the design intent. The operator, the organisation that will run the facility, witnesses from start-up onwards. The certifier, where Tier Certification of Constructed Facility is pursued, witnesses its own demonstrations.

Titles do not settle the allocation. A commissioning agent appointed by the contractor directs and records testing on the contractor’s side; a commissioning manager or commissioning authority appointed by the owner judges the result. On some projects one firm holds both appointments, which places execution and judgement with the same party. The matrix should use four marks, each with one meaning: execute, to carry out the test and record the result; witness, to attend and sign the record as observed; review, to check the procedure before the test and the results after it against the design; and accept, to declare the level complete for the owner, so that the next level may start.

Levels 1 and 2: factory and installation

Level 1, the factory acceptance test, verifies an item of equipment against its specification at the works: a UPS module at full load and through its transfers, a generator through its load steps, a switchboard through its interlocks and protection. The vendor executes, to a procedure the commissioning manager and the owner’s engineer have reviewed. The installing contractor, which normally holds the purchase order, witnesses with the commissioning manager, and the commissioning manager’s acceptance authorises shipment. The record is the signed test report, the calibration certificates of the test instruments, the deviations with their disposition and the release to ship.

Level 2 verifies the installation against the drawings and the manufacturer’s instructions before anything is energised: model and rating against the approved submittal, clearances, labelling, termination torque, insulation resistance, earthing continuity, and the pressure testing and flushing of pipework. For low-voltage installations, IEC 60364-6 sets out the initial verification. The installing contractor executes and completes the checklists. The vendor reviews the installation of its own equipment, because its warranty and its start-up depend on it. The commissioning manager witnesses a defined sample, reviews every checklist and accepts the level as the prerequisite for energisation.

Level 3: start-up and energisation

Level 3 brings each item of equipment into service for the first time. The vendor executes the start-up to its own procedure, with the installing contractor operating the switching, the isolations and the permits to work. Protection settings are applied from the approved coordination study and confirmed by secondary injection, and the record holds the settings as applied, not the settings as designed. The commissioning manager witnesses and accepts. The operator should witness from this level onwards, because start-up is the first time its staff see the plant run under the safety regime they will take over. The record is the start-up report for each item, the protection settings as applied, the injection results and the energisation permits.

Levels 4 and 5: functional and integrated tests

Level 4 takes each system through its sequences of operation: every mode, every alarm and every failure response, at the loads the system can be given before the facility is complete. The commissioning agent or manager writes the scripts from the sequence of operations, and the owner’s engineer reviews them. The installing contractor executes with its controls specialist, and the commissioning manager and the operator witness. The record is the script with the expected and the actual result on each line, the trend logs from the building management and power monitoring systems, and the issues raised.

Level 5, the integrated systems test, takes the facility at design load, with load banks in place of the IT equipment, through the failure and maintenance scenarios that the resilience objective implies. Here the matrix has to name three authorities that earlier levels do not need: who starts each scenario, who may hold or abort it, and who declares it passed. The stop rules are written before the test, for example a cold-aisle temperature limit at or below 27 °C, the upper bound of the ASHRAE TC 9.9 recommended range, or the trip of a load bank. The installing contractor executes, the commissioning manager witnesses and declares each scenario passed or failed, and the owner’s engineer, the operator and, where engaged, the certifier witness.

Conflicts the matrix has to settle

Two conflicts recur. The first is the installer judging its own test. If the party that installed a system also accepts its test, a failed result can be recorded as a pass with a comment; in the matrix, execution and acceptance never sit in the same column. The second is the vendor writing the only acceptance criteria. A factory procedure written by the vendor alone tends to test what the equipment does well. The criteria should come from the specification and the design basis, and the vendor’s procedure is reviewed against them before the test is scheduled.

A third question is retesting. The matrix should state who pays for a retest after a failure, who authorises it and whether the witnesses must attend again. Left unstated, a retest becomes a commercial dispute at the point in the programme with the least time to resolve one. UBIK, when appointed as commissioning manager, reviews, witnesses and accepts on the client’s behalf and does not execute tests.

What the record should contain at close-out

At handover the commissioning record should contain, for each level and each system, the approved procedure, the signed result sheets with the witnesses named, the deviations and their closure, the retests and the calibration certificates of the instruments used. It should also contain the protection settings as applied, the sequence of operations as finally tested, the trend data from Levels 4 and 5, and an index that connects each requirement in the Owner’s Project Requirements to the test that demonstrated it. Any requirement that was not demonstrated is listed as such, with the reason and the operating limitation it leaves.

The commissioning manager keeps the evidence register during the project. At handover the record passes to the owner and the operator, who keep it for the life of the facility, and the certifier receives the evidence for its own demonstrations.